The invention relates to a setting tool for inserting an anchor rod into a borehole with a housing, which has a receptacle for the anchor rod, into which the anchor rod can be inserted in the longitudinal direction and secured therein. The invention additionally relates to a method for installing an anchor rod using such a setting tool.
Setting tools are used to insert anchor rods into a borehole in which they are anchored by means of a curable compound, such as a chemical mortar cartridge. These anchor rods usually do not have any points of attack for a tool such as a hexagonal wrench. The setting tool must thus act directly on the anchor rod.
Setting tools that can be screwed onto the thread of such an anchor rod, for example, are known from the prior art. However, with these setting tools, the anchor rod can be inserted only by rotating in one direction because the setting tool would be unscrewed from the anchor rod, i.e., from the thread of the anchor rod, if rotated in the opposite direction.
One solution to this problem is possible by means of a setting tool, which is tightened onto the thread, for example, by means of two nuts, which are tightened against one another. However, one problem with this setting tool is that the nuts must be screwed on and tightened in a separate operation, and the tightened connection cannot be loosened until after the curable compound has set up, because the anchor rod must be secured in order to release the tool. It is therefore very time consuming to work with such a setting tool because it is possible to continue working only after the curable compound has set up.
However, setting tools which hold the anchor rod on the thread are designed in principle for only one thread size, a separate tool is needed for each different diameter of the anchor rods.
However, there are known setting tools which require a special geometry (also known as an entraining geometry) on the anchor rods, for example, a hexagonal connection. These anchor rods are considerably more expensive and limit the flexibility of the entire anchor system with regard to the flexibility of the depth of the anchoring and the thickness of the component to be secured.
The object of the invention is to provide a flexible setting tool with which various anchor rods or even anchor rods without a thread can be used. No special entraining devices or entraining geometries are required on the anchor rods. Furthermore, no additional efforts are required with regard to temporary mounting of auxiliary tools and/or nuts or the like.
This object is achieved by the fact that at least one clamping element is provided with a setting tool of the type defined in the introduction; it is assigned to the receptacle, which is inclined at an angle to the longitudinal axis of the receptacle and is supported in a guide in the receptacle in such a way that the clamping element can be moved in the receptacle by rotating the housing in relation to the anchor rod out of a receiving position, in which the anchor rod can be inserted into the receptacle in the longitudinal direction, and into a clamped position, in which the anchor rod is secured in the receptacle in the circumferential direction and therefore the anchor rod follows the movement of the setting tool.
The object of the invention is to clamp the anchor rod on its outside circumference in a frictionally locked manner in the circumferential direction and in a form-fitting manner in the direction of insertion. Therefore, the anchor rod can be secured, regardless of the thread and/or the tool screwed onto the thread. After insertion of the anchor rod, at least one clamping element is moved radially inward from the receiving position until it is in contact with the anchor rod. Because of the inclined position of at least one clamping element in the housing of the setting tool, which is achieved due to the angle of tilt, the setting tool rolls on the outside circumference of the anchor rod, pulling the anchor rod into the setting tool so that the anchor rod becomes clamped with it. It is thus possible to adapt to various anchor rod diameters, depending on the radial distance between the starting position and the clamped position.
The anchor rod is secured on the tool and/or in the receptacle without the use of a tool by rotating the entire setting tool in relation to the anchor rod. At least one clamping element may already be loosely in contact with the anchor rod after insertion of the anchor rod into the receptacle, so that the setting tool is displaced by rotation of the receptacle due to the friction between the clamping element and the anchor rod in the receptacle, such that it is moved into the clamped position. However, the clamping element may also be moved from the starting position into the clamped position because of the forces of inertia.
The clamping element is preferably in contact with the anchor rod with the largest possible clamping surface, for example, to prevent damage due to the clamping on a thread that is provided on the anchor rod. Accordingly, the angle of attack is selected to yield secure clamping and the largest possible clamping surface.
The housing is preferably designed to be essentially cylindrical, with a bottom plate that has an opening for insertion of the anchor rod and with a cover plate opposite the bottom plate, these two plates being connected to one another by one or more connecting means. There is preferably no limit to the connecting means here. The plates may be connected to one another by means of a lateral surface that is partially or completely closed or by means of other connecting means, such as screws, rods, struts and the like. Alternatively, the cover plate or bottom plate may also be designed with a cup shape, so that special connecting means may be largely omitted. The anchor rod may be inserted through the opening in the bottom plate in the direction of the longitudinal axis of the cylinder until the anchor rod comes to rest against the cover plate. Securing the rod in the longitudinal direction of the anchor rod may also be achieved through the cover plate. However, the anchor rod must not be in contact with the cover plate at the start of assembly, i.e., when setting the anchor rod.
The guidance for at least one clamping element is formed by a groove in the bottom plate and in the cover plate, for example. This permits simple support of the clamping element without any additional components.
Depending on the desired clamping effect, the groove defines a linear or curved path on which the clamping element is guided from the receiving position into the clamping position on the anchor rod. Due to the shape of the groove, it is possible to have an influence on how rapidly the clamping element is guided on the anchor rod and/or how great the clamping force is. This path is preferably designed as a spiral that tapers toward the midpoint of the receptacle, so that due to a shallow inclination of the spiral, a very gradual approach of the clamping element to the anchor rod is achieved but therefore also a higher clamping force can be exerted on the anchor rod. On the other hand, due to a steeper inclination accordingly, a very rapid guidance of the clamping element, i.e., clamping at a very low rotation of the housing relative to the anchor rod is possible. However, a higher rotational force accordingly is required to apply high clamping forces.
In order for at least one clamping element(s) to be arranged at an angle of tilt to the axis of the setting tool and/or of the anchor rod, the grooves in the cover plate and in the bottom plate are arranged at an offset in the circumferential direction. As a result, the setting tool is pulled relative to the anchor rod in rotation of the housing, so that the head of the anchor rod is forced against the cover plate and is supported thereon. The offset of the grooves, i.e., the angle of tilt of the clamping element, is to be set as a function of the desired direction of rotation because such a tool can be used in only one direction of rotation. It is possible in this way to define whether the anchor rod can be in right-handed or left-handed rotation of the setting machine (pneumatic drill, screwdriver). This has the advantage that depending on the (exterior) structure of the part of the anchor rod that is inserted into the borehole, where the structure may optionally have the function of an Archimedean screw, the direction of rotation of the setting tool can be selected so that the curable compound in the borehole is not conveyed out of the borehole during or after the setting process.
For example, the clamping element has a bolt or a screw, which extends essentially in the longitudinal direction through the housing and in particular is supported in the bottom plate and in the cover plate.
For example, a clamping jaw with which the clamping element can act on the anchor rod is supported on the bolt or the screw. The clamping jaw offers a sufficiently large contact surface area to form a contact pressure surface or rolling surface distributed over a large area on the anchor rod. The length of the setting tool, which surrounds the anchor rod, preferably amounts to max. 80% of the length of the part of the anchor rod that protrudes out of the substrate after setting the rod. This therefore ensures that the housing of the setting tool will not come to rest on the substrate when turning the anchor rod. Otherwise the tool or the substrate could be damaged. However, the planned excess of material of the curable compounds that are displaced by the anchor rod may emerge from the borehole into which the anchor rod is inserted without soiling the tool.
The clamping jaw is preferably a roller, which is mounted to rotate around the bolt or the screw and is made of a softer material, for example, a plastic or a rubbery material which has a high wear resistance in particular. By rotating the clamping jaw in displacement of the clamping element from the receiving position into the clamping position, it is ensured that there will not be any excessive wear due to friction on the anchor rod or on the clamping element because the roller is rolling on the anchor rod to a certain extent. Since the roller is made of a softer material, it is more adaptable to the anchor rod. However, the material is softer than the anchor rod, which is usually made of metal, e.g., steel. Damage to the anchor rod is therefore reliably prevented.
The bolt or the screw is mounted with guide elements in the guide in particular in the groove, for example, so that the guide elements set the angle of inclination at which the clamping element is inclined to the longitudinal axis of the receptacle. The inclination is set by the guides arranged with an offset in the circumferential direction. The guide elements have supporting surfaces, which are arranged perpendicular to the longitudinal axis of the clamping elements, so that despite the angle of tilt, a planar contact surface is provided for the clamping elements. However, simple sliding of the bolt or the screw in the groove or the guide is ensured by the guide elements.
To presecure the anchor rod in the receptacle, so that the anchor rod cannot fall out before the clamping elements are displaced into the clamping position, the opening of the bottom plate is preferably designed to be elastic for presecuring the anchor rod. The anchor rod is therefore centered in the receptacle. Secondly, the anchor rod cannot slip out of the receptacle. The flexible opening also prevents soil from penetrating into the receptacle, so that reliable functioning of the clamping element is ensured. The opening is preferably designed as a rubber collar.
To achieve the most uniformly distributed clamping force, three clamping elements are preferably provided, arranged so they are distributed uniformly around the anchor rod in the circumferential direction.
The tool preferably has a fastener for a setting machine, for example, a drilling machine, to be able to rotate the setting tool and thus the anchor rod and/or to move it in the direction of a borehole.
In addition, a method according to the invention is provided for installing an anchor rod with a setting tool according to the invention. In this method, the anchor rod is first inserted into the receptacle of the setting tool in the longitudinal direction. Then the anchor rod is inserted into a borehole with the help of a setting tool and the setting tool is started. The setting tool here is rotated in the direction of rotation in relation to the anchor rod, so that at least one clamping element is guided against the anchor rod, rolls on it and therefore clamps the setting tool with the anchor rod. In this clamped condition, the anchor rod is then tightened into the borehole filled with the chemical mortar until reaching the desired position. Then the setting tool is simply released again by turning the setting tool opposite the direction of rotation in setting the anchor rod.
Additional advantages and features are derived from the following description in conjunction with the accompanying drawings.